VBWG Potential role of PPAR activation in CV risk reduction Adapted from Tenenbaum A et al. Intl J Cardiol. 2004;97: Atherosclerosis Insulin resistance Hyperinsulinemia Obesity Food intake excess Genetic background Physicalinactivity PPAR modulation Dyslipidemia Hyperglycemia Inflammation Hypercoagulation Hypertension

VBWG Plutzky J. Science. 2003;302: Peroxisome proliferator-activator receptors (PPARs): Overview Family of steroid hormone nuclear receptors Three isotypes identified –PPAR  –PPAR  –PPAR  Ligand-activated transcription factors regulating metabolic processes

VBWG Adapted from Plutzky J. Science. 2003;302: PPAR activation and atherosclerosis: A hypothesis Blunts atherosclerosis Indirect Fat, liver, skeletal muscle Ligand endogenous or synthetic Activated PPAR receptor Reduces inflammation Direct Vascular and inflammatory cells  FFA  Glucose  Insulin sensitivity  Triglycerides  HDL  Cytokines  Chemokines  Cholesterol efflux  Adhesion molecules ?? ??

VBWG Focus on PPAR  activation Inzucchi SE. JAMA. 2002;287: Reduces insulin resistance Preserves pancreatic  -cell function Improves CV risk profile Improves dyslipidemia (  HDL,  LDL density,  or  TG)  Renal microalbumin excretion  Blood pressure  VSMC proliferation/migration in arterial wall  PAI-1 levels  C-reactive protein levels  Adiponectin  Free fatty acids

VBWG PPAR  modulators *Withdrawn March 2000 † Also available in combination with metformin or sulfonylurea ‡ Also available in combination with metformin § Dual PPAR  /  agonist Name Trade name Manufacturer Approval status Troglitazone Rezulin  Parke-Davis1997* Rosiglitazone † Avandia  GlaxoSmithKline1999 Pioglitazone ‡ Actos  Eli Lilly/1999 Takeda Pharmaceuticals Muraglitazar § Pargluva  Bristol-Myers Squibb/NDA Merck submitted 2004

VBWG PPAR modulation: Newest strategy in CV risk reduction Adapted from Tenenbaum A et al. Intl J Cardiol. 2004;97: Insulin resistance Hypercoagulation Inflammation Hypertension Dyslipidemia PPAR modulation Hyperglycemia Hyperinsulinemia

VBWG Factors that may drive the progressive decline of  -cell function Adapted from Kahn SE. J Clin Endocrinol Metab. 2001;86: Adapted from Ludwig DS. JAMA. 2002;287: Hyperglycemia (glucose toxicity)  -cell Insulin resistance “Lipotoxicity” (elevated FFA, TG)

VBWG TRIPOD: Evidence that insulin resistance causes  -cell failure PPAR  activation: 55% relative risk reduction for new-onset diabetes (HR 0.45; 0.25–0.83) Effect was most prominent in women with initial increase in insulin sensitivity and accompanying large reduction in insulin output Protection persisted 8 months after cessation of active treatment PPAR  activation associated with preserved  -cell function N = 266 Hispanic women with gestational diabetes randomized to troglitazone 400 mg or placebo for median 30 months Buchanan TA et al. Diabetes. 2002;51: TRIPOD = Troglitazone in Prevention of Diabetes

VBWG DPP: Improving insulin sensitivity/ secretion prevents diabetes N = 3234 DPP Research Group. Diabetes. 2005;54: pyr = person years IGR = insulin-to-glucose ratio DPP = Diabetes Prevention Program Diabetes hazard rate (per 100 pyr) PlaceboMetforminLifestyle Insulin secretion (IGR) Low High Insulin sensitivity (1/fasting insulin) Medium Insulin secretion (IGR) High Medium Low Low Medium High

VBWG PPAR  activation blunts progression to diabetes DPP Research Group. Diabetes. 2005;54: *Terminated early after 1.5 years Diabetes Prevention Program Cumulative incidence (%) Years Placebo Metformin 850 mg Lifestyle Troglitazone 400 mg* n =  75% vs placebo P < 0.001

VBWG PPAR  activation improves  -cell function Ovalle F, Bell DSH. Diabetes Care. 2004;27: Acute insulin response to glucose (µIU/mL/10 min) – Insulin Rosiglitazone 8 mg P = 0.02 Disposition index HOMA-IR N = 17 with type 2 diabetes HOMA-IR = Homeostasis model assessment of insulin resistance Disposition index =

VBWG CV implications of insulin resistance and PPAR  activation Adapted from Tenenbaum A et al. Intl J Cardiol. 2004;97: Insulin resistance Hyperinsulinemia Hypercoagulation Inflammation Hypertension Hyperglycemia Dyslipidemia PPAR modulation Dyslipidemia

VBWG Importance of LDL particle density In insulin resistance, LDL-C levels are similar or only slightly elevated vs general population However, atherogenicity of LDL particles varies according to density – More dense = more atherogenic Proportion of small, dense LDL particles greater in patients with insulin resistance or diabetes vs general population Miranda PJ et al. Am Heart J. 2005;149:33-45.

VBWG Greater atherogenicity of small, dense LDL vs normal LDL Adapted from Sniderman AD et al. Ann Intern Med. 2001;135: Susceptible to oxidation Binds to arterial wall Penetrates arterial wall Toxic to endothelial cells Promotes PAI-1 production by endothelial cells Promotes thromboxane production by endothelial cells Accumulates Ca 2+ in vascular smooth muscle cells Binds to LDL scavenger receptor

VBWG Increased small, dense, LDL particles associated with reduced IHD survival St-Pierre AC et al. Arterioscler Thromb Vasc Biol. 2005;25: N = 2072 men without IHD at baseline;13-year follow-up Survival probabilities Follow-up (years) P < Tertiles of LDL-C 255Å <1.07 mmol/l 1.07–1.86 mmol/l≥1.86 mmol/l IHD = ischemic heart disease

VBWG PPAR  activation increases LDL size and buoyancy Brunzell JD et al. Circulation. 2004;110(suppl):III-143. N = 302; rosiglitazone 8 mg LDL particle size LDL density  Diameter vs baseline (Angstroms)  Relative flotation vs baseline P <

VBWG Comparative effects of PPAR  activators on lipids in diabetes 1 Goldberg RB et al. Diabetes Care. 2005;28: Plotkin DJ et al. Diabetes. 2005;54(suppl 1):A Khan M et al. Diabetes. 2005;54(suppl 1):A137. In patients not receiving statin therapy, studies suggest that pioglitazone and rosiglitazone have differing effects on lipid levels and particle size 1 In patients receiving statin therapy, some studies suggest these differences are eliminated, while other studies suggest they persist 2 Clinical implications are not known 3

VBWG CV implications of insulin resistance and PPAR  activation Adapted from Tenenbaum A et al. Intl J Cardiol. 2004;97: Insulin resistance Hyperinsulinemia Hypercoagulation Inflammation Hypertension Hyperglycemia Dyslipidemia PPAR modulation Inflammation

VBWG Adipokines: An overview CRP IL-6 PAI-1 Angiotensinogen Leptin Resistin MCP-1 Adiponectin Lau DCW et al. Am J Physiol Heart Circ Physiol. 2005;288:H Wellen KE, Hotamisligil GS. J Clin Invest. 2005;115: Atherogenic Antiatherogenic

VBWG Adiponectin associated with decreased risk of MI PischonT et al.JAMA. 2004;291: Adjusted relative risk (P < 0.001)Lipid-adjusted relative risk (P < 0.02) Quintile ofadiponectin(95% CI) N = 18,225 men; 6-year follow-up  g/mL Relative risk

VBWG Improved insulin sensitivity associated with increased adiponectin N = 40 women with gestational diabetes treated with troglitazone for 3 months Pajvani UB et al. J Biol Chem. 2004;279: % Change in insulin sensitivity (  S i ) –50 – % Change in HMW/total adiponectin (  S A ) –

VBWG Lau DCW et al. Am J Physiol Heart Circ Physiol. 2005;288:H Contrasting roles of CRP and PPAR  on inflammation and insulin resistance Adipose tissue Liver  IL-6 PPAR   CRP  Glucose Insulin resistance

VBWG Direct relationship of CRP to metabolic syndrome Women’s Health Study; N = 14,719 Ridker PM et al. Circulation. 2003;107: Median CRP (mg/L) Components of the metabolic syndrome (n) n = Modified ATP III definition

VBWG Inflammation is a contributing mechanism in diabetes development Festa A et al. Diabetes. 2002;51: Fibrinogen CRP PAI-1 P = 0.06P = st 2nd 3rd 4th N = 1047 Quartiles of inflammatory proteins Incidence (%)

VBWG PPAR  activation decreases CRP in patients with diabetes Mean change from baseline (%) Haffner SM et al. Circulation. 2002;106: % –50 –40 –30 –20 –10 0 Placebo Rosiglitazone 4 mg Rosiglitazone 8 mg 22% P < 0.05 N = 357; 26 weeks

VBWG CV implications of insulin resistance and PPAR  activation Adapted from Tenenbaum A et al. Intl J Cardiol. 2004;97: Insulin resistance Hyperinsulinemia Hypercoagulation Inflammation Hypertension Hyperglycemia Dyslipidemia PPAR modulation Hypertension

VBWG Raji A et al. Diabetes Care. 2003;26: –20 – –2–10123 Change in insulin sensitivity (mg/kg/min)  in 24-h systolic BP (mm Hg) P < r = –0.59 N = 24 nondiabetic hypertensives; rosiglitazone 8 mg, 16 weeks Improved insulin sensitivity associated with reduced BP VBWG Nonmodulators Low-renin hypertension

VBWG PPAR  activation associated with sustained BP reduction N = 668 with type 2 diabetes Home PD et al. Diabetes. 2005;54(suppl 1):A134. –6–5–4–3–2– h systolic BP * Reduction from baseline (mm Hg, 95% CI) –5–4–3–2– h diastolic BP * Treatment differences (mm Hg, 95% CI) 6 months 12 months Baseline sulfonylurea 6 months 12 months Baseline metformin * Ambulatory BP Rosiglitazone added to baseline therapy

VBWG Adapted from Tenenbaum A et al. Intl J Cardiol. 2004;97: CV implications of insulin resistance and PPAR  activation Insulin resistance PPAR modulation Hyperinsulinemia Hypercoagulation Inflammation Hyperglycemia Dyslipidemia Hypertension

VBWG PPAR  activation blunts TNF-  –induced PAI-1 secretion Hamaguchi E et al. J Pharmacol Exp Ther. 2003;307: Trog = troglitazone *P < † P < Human umbilical-vein endothelial cells PAI-1 (ng) * † TNF-  1 ng/mL TNF-  10 ng/mL TNF-  1 ng/mL + Trog 10 µM TNF-  10 ng/mL + Trog 10 µM TNF-  100 ng/mL + Trog 10 µM TNF-  100 ng/mL *

VBWG BasalPlacebo Metformin 2.5 g PAI-1 activity (U/mL) * P = vs placebo Results at 12 weeks  A1C = –1.3%  FPG = –55 mg/dL * N = 27, 12 weeks Metformin reduces PAI-1 levels in type 2 diabetes Nagi DK, Yudkin JS. Diabetes Care. 1993;16:621-9.

VBWG Weissman PN et al. Diabetes. 2004;53(suppl 2):A28. – 9.8 – –40 –30 –20 – CRPPAl-1 MMP-9 – 26.9 – – *NS vs baseline  Baseline (%) Metformin 2 g (n = 70)Metformin 1 g + rosiglitazone 8 mg (n = 57) P = P < P = Benefits of combined insulin sensitizer therapy: Effects on CRP, PAl-1, and MMP-9 * * Weeks 8–24